Hydraulic garage jack

ABSTRACT

A garage jack, the load is lowered by depressing a pedal at the end of a pedal arm. To prevent the load from being lowered by unintentional depression of the pedal, the pedal arm is divided into an outer portion connected with the pedal proper, and an inner portion. The portions are adapted to be disengaged from each other such that in disengaged position the pedal cannot effect lowering of the load.

United States Patent [191 B'o'rk Jan. 22 1974 [54] HYDRAULIC GARAGE JACKPrimary ExaminerCharles J. Myhre 75 I t B A d B k E kl t men or 3:52 erss una Assistant Exam1ner-Frank H. McKenzie, Jr.

Attorney, Agent, or FirmE1liott I. Pollock et a1. [73] Assignee:Domkraft AB Nike, Eskilstuna,

Sweden 22 Filed: I Apr. 6, 1972 ABSTRACT 1 PP Nod 241,548 A garage jack,the load is lowered by depressing a pedal at the end of a pedal arm. Toprevent the load 52 us. or 74/5 12, 74/469, 74/524 from being lowered byunintentional depression of the [51] Int. Cl G05g 1/14 P the Pedhll armis divided into an outer portion 581 Field of Search 74/524, 519, 512,491; connected with the Pedal Proper, and an Inner P 254/2 R 8 R, 8 B, 8C tion. The portions are adapted to be disengaged from each other suchthat in disengaged position the pedal [56] References Cited cannoteffect lowering of the load.

5 Claims, 5 Drawing Figures MENTEUJAN 22 H?" SHEET 2 BF 3 HYDRAULICGARAGE JACK BACKGROUND OF THE INVENTION This invention relates to ahydraulic garage jack of the kind comprising a control means to actuatemeans for lowering the lifting means of the jack.

When one is working underneath a vehicle, which is held in liftedposition by the lifting means of the jack, it may happen that therelease pedal-of such a jack is depressed unintentionally. The resultinglowering of the vehicle involves the risk of severe accidents.

SUMMARY OF THE INVENTION Such accidents are prevented by a safety deviceon the jack accordingto the present invention, which is characterized inthat it comprises means to render the lowering means of the jack by thecontrol means at least when the control means is actuated in the sameway as for lowering the lifting means. Thus, when a mechanic is workingbelow the vehicle, the release pedal can be entirely disengaged fromthe-release valve. When the load is to belowered, the pedal can beactuated only by an intentional manipulation. The pedal can be engagedonly by a double movement, viz. by being lifted upwards and pushedinwards by hand or foot. In disengaged position, the pedal cannot beengaged by unintentional horizontal forces, for example from a tool orother objects possibly striking against the jack in operation.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention isdescribed in the following, with reference to the accompanying drawing,in which FIG. 1 by a lateral view shows the rear end of the jack 'withdisengaged release pedal,

FIG. 1A in greater detail shows the coupling of the release pedal whenthe pedal is in engaged position,

FIG. 2 shows a view from above of the device according to FIG.- 1,

' FIG. 3 shows an alternative coupling means for the release pedal whenthe pedal is disengaged, and

FIG. 3A shows the device according to FIG. 3 when the pedal is engaged.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The jack is movable onwheels 1 below the object to be lifted. The lifting means proper islocated at the front end (not shown) of the jack. For elevating thelifting means, a pump handle 2 is provided at the rear end of the jackwhere it is rotatably supported about a shaft 3. Upon lifting andlowering the handle, a piston in a pump cylinder 4 is reciprocated andcauses a pressure fluid to elevate the lifting means.

For lowering the lifting means, a control arm is provided, whichcomprises a pedal portion 5 coupled together with an inner arm portion6. The coupling includes a horizontal axle journal 7 extendingtransversely through the inner arm portion 6. At said journal 7 theinner arm portion 6 is surrounded by a pair of legs 8 in a fork-likemanner, which legs constitute the inner end of the pedal portion 5. Eachof said legs is provided with an elongated hole 9 by means of which thepedal portion 5 is supported on the axle journal 7, and which holespermit movement of the pedal portion between two positions in itslongitudinal direction relative to the inner arm portion 6. I

The outer end of the inner arm portion 6 includes an upwardly projectingedge 10 adapted to engage with a corresponding recess 11 in the lowersurface of that part of the pedal portion 5 which connects the legs 8.In FIG. 1A the edge 10 and recess 11 are shown engaged with each other.The pedal portion 5 is then in inserted position. Upon depression of thepedal portion 5 the inner arm portion 6 is then moved along with themovement of the pedal portion 5. Uponlifting of the pedal portion 5,however, it can turn about the axle journal 7 without also moving theinner arm portion 6. Due to the inclination of the edge 10, the pedalportion 5 by itself cannot slide out of the engagement with the edge 10when the coupling position is as shown in FIG. 1A.

The pedal portion 5 is disengageable from the inner arm portion 6. Forits disengagement, the pedal portion is pulled out in its longitudinaldirection, whereby the condition shown in FIG. 1 is obtained. The edge10 has been disengaged from the recess II. The pedal portion 5 now restswith an edge 12 against the pump cylinder 4. Any unintentional loweringof the lifting means is prevented effectively, because upon depressionof the pedal portion the inner arm portion 6, due to the edge 12becoming a fulcrum, is actuated by a lifting rather than a loweringforce from the axle journal 7. In the alternative coupling arrangementaccording to FIG. 3, the edge 10 and recess 11 with respect to theirfunction are replaced by an L-shaped groove 9A in each of the legs 8.Consequently, the coacting stop surfaces 10A and 11A can be given planeshape.

The inner arm portion 6 is supported rotatably about a shaft 13 in thejack. Upon raising of the inner end of the inner arm portion 6, therelease valve, which is located in a housing 14, is actuated in that avalve element 15 is permitted to raise, and the lifting means islowered. The element 15 normally is held depressed, and thereby therelease valve non-operative, by means of a compression spring 16, whichtends to turn the arm portion 6 clockwise and thereby holds the innerend of the arm portion pressed against said element 15. The spring 16 inFIG. 1A also holds the pedal portion 5 in upper position, and it isagainst the action of spring 16 that the pedal portion 5 is depressedwhen the jack is to be released.

With the jack shown in the drawings, the pedal portion 5 (see FIG. 2)serves as the only carrying handle when the jack is transported bycarrying it. The pedal portion 5, therefore, normally is disengaged fromthe arm portion 6 when the arm portion is placed below the vehicle. 1

What I claim is: 1. A hydraulically operated garage jack comprising incombination,

means for hydraulically raising a lifting means, release means for attimes actuating said first named means to lower said lifting means, anda release pedal operatively connected to said release means foractuating said release means, said release pedal being manually operablebetween a first position in which said release pedal is ineffective toactuate said release means and a second position in which said releasepedal is effective to actuate said release means.

2. The jack of claim 1 in which said release means comprises a pivotallymounted inner arm member and a release valve actuated in response to thepivoting of said inner arm member, said release pedal in its secondposition engaging said inner arm member to permit actuation of saidvalve in response to actuation of said release pedal.

3. The jack of claim 2 wherein said release pedal comprises a U-shapedend portion whose legs are pivotally supported on a free end of saidinner arm member, the pivoted support for said release pedal on saidinner arm member comprising an axle and a cooperating elongated aperturepermittng longitudinal movement of said release pedal relative to thepivot, said release pedal having the bight portion of its U-shaped enden- 'portion which bears against said inner arm member to effectrotation thereof about its pivot only when said release pedal has beenmoved to one end of its permissible longitudinal motion.

(5/03) "1 1 r 1 w 'fi r 1' CERTH lQA I In 01* (,ORRhC i EON Patent No.3,786,692 Dated January 22, 1974 Inventor(s) BENGT ANDERS BJORK It iscertifieu chat error appears in the abAe-identified patent and that saidLetters Patent are hereby corrected as shown below:

Foreign Application Priority Data April 6, 1971 Sweden, .4472/71 Signedand sealed this 23rd dag, of April 1971 .0

( SEAL) Attest:

'BDE'JAI- D I-IJ-LETCEmlLJR, G. MARSHALL DAMN Attosting OfficerCommissionor of Patents

1. A hydraulically operated garage jack comprising in combination, means for hydraulically raising a lifting means, release means for at times actuating said first named means to lower said lifting means, and a release pedal operatively connected to said release means for actuating said release means, said release pedal being manually operable between a first position in which said release pedal is ineffective to actuate said release means and a second position in which said release pedal is effective to actuate said release means.
 2. The jack of claim 1 in which said release means comprises a pivotally mounted inner arm member and a release valve actuated in response to the pivoting of said inner arm member, said release pedal in its second position engaging said inner arm member to permit actuation of said valve in response to actuation of said release pedal.
 3. The jack of claim 2 wherein said release pedal comprises a U-shaped end portion whose legs are pivotally supported on a free end of said inner arm member, the pivoted support for said release pedal on said inner arm member comprising an axle and a cooperating elongated aperture permittng longitudinal movement of said release pedal relative to the pivot, said release pedal having the bight portion of its U-shaped end engaging with a cooperating part of said inner arm member only when said pedal release mEmber has been moved longitudinally toward one end of its permitted motion relative to its pivot on said inner arm member.
 4. The jack of claim 1 wherein said release pedal is pivotally supported on said inner arm member.
 5. The jack of claim 4 wherein said release pedal is slidable longitudinally relative to its pivotal support on said inner arm member, said release pedal including a portion which bears against said inner arm member to effect rotation thereof about its pivot only when said release pedal has been moved to one end of its permissible longitudinal motion. 